Author Topic: Inside the 1250 Motor  (Read 8851 times)

Offline BlueDog

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Inside the 1250 Motor
« on: July 30, 2009, 03:28:34 PM »
I'm taking apart a 1250 motor with under 1700 miles on it. I thought I'd start a thread on what I'm seing as I disassemble it, and maybe I can answer some quesions you guys might have.
I've also posted this stuff on MS, I thought I'd put it here too if that's not bad manners or anything.  :grin:
So far, some interesting things are the valve shims. All the exhaust shims are 165, and all the intake shims are 175. That's the way they came from the factory, this engine has not been adjusted.
The cylinder block is not sleeved. It is all one cast aluminum unit, and the cylinder walls appear to be plated.
Also the cylinders #1 & #2 and #3 & #4 are very close together, there doesn't look like a lot of room for boring this motor out. If you did, you probably couldn't go over 1 millimeter without the walls getting pretty thin between. And I don't know what you'd do when it comes time for new rings, I guess it would have to replace the whole cylinder block, unless you could get it slightly re-bored and then re-plated.
The cam lobes are pretty pointy. they look like they have alot of lift but short duration. Anybody have the specs for the cams?
The tranny gears all all in the top half of the case, on two main shafts. They are straight-cut gears with a slight beveled edge. They look pretty massive.
The clutch pack is HUGE.  :eek:
The cam cover has a big one-piece rubber gasket that fits in a groove that goes all around the edge. The rubber half-round end caps are part of the gasket and so are the o-rings that fit around the spark plug tunnels. It looks pretty sturdy and should be re-usable.
There's 4 cam caps, 2 journals on each one, with numbers for each bolt. There an oil pipe that connectsthe right front bank to therear bank. When I took them off I had the motor at TDC and loosened the bolts in reverse order according to the numbers, and the cams lifted right out nicely.
I'll put some more stuff up later and if anyone wants to know something just ask and I'll check it out.

Offline Oldbutslow

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Re: Inside the 1250 Motor
« Reply #1 on: August 07, 2009, 08:41:23 PM »
The local dealer tells me they never seen one of these bikes in for service. The one thing that I don't understand is the minimal space between cylinders. I sure would like to have a water passage, but Suzuki knows what they're doing.  ,BK
'07 B1250, '09 TU250X, '01 KE100

Offline Red01

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Re: Inside the 1250 Motor
« Reply #2 on: August 09, 2009, 02:05:46 PM »
The cylinder block is not sleeved. It is all one cast aluminum unit, and the cylinder walls appear to be plated.

That's the process common with Suzuki's GSX-R's and many of their other bikes these days. 
They call it "SCEM" (Suzuki Composite Electrochemical Material).  Supposed to be some pretty tough stuff. Similar processes are used by other makers, too.
Paul
2001 GSF1200S
(04/2001-03/2012)
2010 Concours 14ABS
(07/2010-current)


Offline BlueDog

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Re: Inside the 1250 Motor
« Reply #3 on: August 22, 2009, 10:47:16 AM »
You can see how close they are




Offline BlueDog

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Re: Inside the 1250 Motor
« Reply #4 on: August 22, 2009, 10:51:20 AM »
The head





Pistons



Here's what the shim-under-bucket looks like


Offline allan4169

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Re: Inside the 1250 Motor
« Reply #5 on: August 29, 2009, 02:19:38 AM »
So I am looking at all of your pictures on the PixPipeline site and what did you do to those starter gears? Both side covers have been scraped down pretty good.
I also believe that when they do a valve adjustment shech they have to measure the valve gap, remove the camshafts, replace the shim with the corrected
clearence , reinstall the camshafts, and check the clearence again. If I am wrong in this, please let me know. Also I see that they got away from the seperate alternator and went back to the end of crank alternator like my 83 GSX 750. Otherwise keep the info coming.

Offline BlueDog

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Re: Inside the 1250 Motor
« Reply #6 on: August 29, 2009, 09:51:27 AM »
Those starter gears are from my bike. They were broken by the previous owner. I bought it cheap because of that fact. When I looked around to replace the parts, it made more sense to buy this salvage motor than to buy the starter gear parts seperately. It would have cost over $1K for a new starter motor, idler gear, clutch gear, stator and rotor.
The motor came from a bike that was laid down and writen off at 1670 miles, that's why the sidecovers on it are scratched. That's why they're only $25. I think I'll grind & polish them myself, then sell them at a better (for me) price.  :trustme:
You are correct on the valve adjustment procedure. Here' some better close-ups of the shims under the buckets,

With the bucket removed and shim in place on top of the valve stem



With the shim laying inside the bucket



I used a strong magnet to pull the buckets up off the valve springs. Sometimes the shim stayed on top the valve stem and sometimes they came up with the bucket.
All the exhaust shims were .165 and the intakes were .175 from the factory.





Offline mademiriam

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Re: Inside the 1250 Motor
« Reply #7 on: August 29, 2009, 10:25:39 PM »
the valve buckets are probably the same on a lot of suzukis, I know they look just like the SRAD ones I got a close look at this spring.
'05 Bandit 1200, Full Muzzy, Dyno jet stage 1, 5 degree ignition advancer, Galfer SS Lines, EBC rotors, busa shock, busa forks
'03 R6 trackbike

Offline BlueDog

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Re: Inside the 1250 Motor
« Reply #8 on: August 30, 2009, 04:06:39 AM »
I think you're right, Suzuki is known for using interchangeable parts amongst various modes so the shim/buckets are probably the same as say, GS or maybe GSXR models. I don't have a lot of experience with their street bikes, but I've had a few Suzuki dirtbikes and enduros.
Personally I prefer Kawaski's shim/bucket system, they use a much bigger shim located on top of the bucket instead of underneath, the cam lobe runs directly on the shim which is held in place by a lip around the top edge of the bucket. You only have to raise the cams far enough to slip the shims in & out, no need to mess with realigning the cam chain/sprockets, and the shim takes all the wear from the cam instead of the bucket itself.
Now that I have the Bandit running tho, my old GyPZy 1100 hasn't been touched, poor thing. I still love her, tho.  :grin:

Offline Red01

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Re: Inside the 1250 Motor
« Reply #9 on: September 17, 2009, 05:15:55 PM »
While the Kawi system is easier from a maintenance standpoint, the Suzuki style can't spit shims.
I still prefer the screw & locknut setup like the B12 uses over any bucket setup from a maintenance viewpoint.
Paul
2001 GSF1200S
(04/2001-03/2012)
2010 Concours 14ABS
(07/2010-current)


Offline BlueDog

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Re: Inside the 1250 Motor
« Reply #10 on: September 18, 2009, 02:24:17 AM »
While the Kawi system is easier from a maintenance standpoint, the Suzuki style can't spit shims.

Yep. It's theoretically stronger and more reliable under high-stress conditions like racing. But hammering on my GPz for 20 years including some trips to the track, I've never broken a shim. As far as I know (and correct me if I'm wrong), I've never heard of any major consistent valve failures in Kawasaki's long career of racing. It's an excellent design for the average self-maintinence guy and I wish Suzuki had a similar system that's all.

Not taking anything away from Suzuki because I'm loving my new Bandit. But to be honest, I'm not relishing doing the valves. I have a feeling it won't be near as often tho.

I still prefer the screw & locknut setup like the B12 uses over any bucket setup from a maintenance viewpoint.

'Course you do.  :trustme:

Offline gunzip

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Re: Inside the 1250 Motor
« Reply #11 on: October 12, 2009, 09:59:10 PM »
my old 83 gs1100 shafty 'zuke had the bucket over shim design , it wasn't too hard to deal with; In 28000 miles it never went out of tolerance ! I am hoping the 1250 bandit follows suit cause that sure looks like a royal pain changing those shims